Answer:
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
Step-by-step explanation:
The margin of error of a confidence interval is given by:
In which 
is the standard deviation of the population and n is the size of the sample.
z is related to the confidence level. The higher the confidence level, the higher the values of z, and thus, we wider the confidence interval is.
In this question:
The narrower C.I. is the 95%, and the wider is the 99%. So
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
Answer:
A and B
Step-by-step explanation:
Parallel lines are lines which have the same slope. Perpendicular lines have negative reciprocal slopes.
For the options:
A. Both equations have 7/5 as the slope. They are parallel.
B. The slopes are 1 and -1. These are perpendicular.
C. The slopes are 9/2 and are parallel.
D. The slopes are 7/3 and -3/7. They are perpendicular.
The solution is A and B.
Answer:
9. x>-4 or x≥1
10. a<2 or a≥-5
11. v≤7 or v≥-4
12. k≥5 or k<8
13. n>6.8 and n≤9
Step-by-step explanation:
9. -2x-7>1
-2x>8
x>-4
x-2≥-1
x≥1
10.a/-2 <-1
a<2
-4a+3≥23
-4a≥20
a≥-5
11. 6v+38≤-4
6v≤-42
v≤7
2(v+3)≥-2
2v+6≥-2
2v≥-8
v≥-4
12. 4(1-k)≥-16
4-4k≥-16
-4k≥-20
k≥5
7-6k<-41
-6k<-48
k<8
13. 10n-9>-59
10n>-68
n>6.8
n-6≤3
n≤9
The area of a right triangle with side lengths 7 and 7 is 
Answer:
18.
a) 6k + 2y
b) 2x^2 + 2x
c) 16h
19. 4.5 cm
20.
a) x > 4.5
b) x >= 32
Step-by-step explanation:
